Lee M E, Thrasher T N, Keil L C, Ramsay D J
Am J Physiol. 1986 Sep;251(3 Pt 2):R614-20. doi: 10.1152/ajpregu.1986.251.3.R614.
The relative roles of cardiopulmonary and sinoaortic baroreceptors in the regulation of vasopressin and corticosteroid release were evaluated in conscious dogs. The dogs were prepared with inflatable cuffs around either the ascending aorta, proximal to the brachiocephalic trunk, or the pulmonary artery. Inflation of the cuffs was adjusted to cause a reduction of mean systemic arterial pressure (MAP) of 0, 5, 10, 20, or 30% of control for 1 h in separate experiments. In spite of the profound systemic hypotension caused by constriction of the ascending aorta, plasma vasopressin failed to increase and corticosteroids increased only in response to a 30% decrease in MAP. In contrast, a 5% reduction in MAP during pulmonary arterial constriction increased plasma vasopressin and corticosteroid concentrations significantly. The apparent paradox in these results is correlated with different effects of the two maneuvers on left atrial pressure. Left atrial pressure increased dose dependently during inflation of the ascending aortic cuff but decreased during inflation of the pulmonary arterial cuff. In contrast, graded inflation of the pulmonary arterial cuff caused dose-dependent increases in right atrial pressure, plasma vasopressin, and corticosteroids. Therefore, we conclude that powerful inhibitory signals, arising from the left heart, can inhibit vasopressin and hypotension release in response to systemic hypotension.
在清醒犬中评估了心肺和窦主动脉压力感受器在血管加压素和皮质类固醇释放调节中的相对作用。给犬在头臂干近端的升主动脉或肺动脉周围放置可充气袖带。在单独的实验中，调整袖带充气，使平均体动脉压（MAP）降低至对照值的0%、5%、10%、20%或30%，持续1小时。尽管升主动脉缩窄导致严重的全身性低血压，但血浆血管加压素并未升高，仅在MAP降低30%时皮质类固醇才升高。相反，肺动脉缩窄期间MAP降低5%会显著增加血浆血管加压素和皮质类固醇浓度。这些结果中明显的矛盾与两种操作对左心房压力的不同影响有关。升主动脉袖带充气期间左心房压力呈剂量依赖性增加，而肺动脉袖带充气期间左心房压力降低。相反，肺动脉袖带分级充气会导致右心房压力、血浆血管加压素和皮质类固醇呈剂量依赖性增加。因此，我们得出结论，来自左心的强大抑制信号可抑制血管加压素释放并减轻因全身性低血压引起的低血压。
